Steel fabrications are often employed in the manufacture of components for construction equipment and the like. In the case of an arm for lifting or loading, a fabrication may consist of a somewhat rectangular box section incorporating a pivot and comprising a plurality of substantially flat plates connected together by welding; such an arm can be both strong and of low mass and low inertia.
Care is required during welding to avoid the introduction or creation of concentrations of stress, which may result in failure of the weld in use. In particular high stresses can be produced at the start or at the end of an electro-deposition weld, for example where two plates are joined together by a transverse weld.
In such circumstances, it is conventional to provide a run-on and run-off feature at the end of the joint to be welded, generally in the form of a plate extension or protuberance. The weld is started and stopped on the projection which is at either end of the weld run, and this ensures that over the length of the substantive joint the weld is of substantially consistent quality.
After completion of the weld, the run-on and run-off features, together with the start and end of the deposition weld, are removed by grinding to leave only the welded joint flush with the longitudinal edge of the respective plates. In this way any potential weld defect is removed from the start and stop positions, and a consistently strong fabrication is thus provided.
Nevertheless it would be desirable to further reduce the stress levels at the start and end of such a deposition weld, in particular in the region of a pivot of a box section fabrication.